Marine well completion apparatus



Nov. 16, 1965 a. c. HOWARD 3,217,805

MARINE WELL COMPLETION APPARATUS Filed May 16, 1965 5 Sheets-Sheet 1 l2GEORGE C. HOWARD INVENTOR fifwd/KX/M ATTORN E Y.

Nov. 16, 1965 G- c. HOWARD 3,217,805

MARINE WELL COMPLETION APPARATUS Filed May 16, 1963 3 Sheets-Sheet 2 W J7 V H 1 x I 2 V I i M I y A 1N Akl \I \I 1 31 55* 38 1 GEORGE 0. HOWARDINVENTOR ATTORNEY.

Nov. 16, 1965 G. c. HOWARD 3,217,805

MARINE WELL COMPLETION APPARATUS Filed May 16, 19 63 s Sheets-Sheet 5GEORGE 0. HOWARD INVENTOR- ATTORNEY- United States Patent 3,217,805MARINE WELL COMPLETION APPARATUS George (J. Howard, Tulsa, Okla,assignor to Pan American Petroleum Corporation, Tulsa, Okla, acorporation of Delaware Filed May 16, 1963, Ser. No. 280,930 11 Claims.(Cl. 16666.5)

This invention relates to completing wells in marine locations. Moreparticularly it relates to apparatus for use at the top of the well topermit completing the well without the use of a platform but stillallowing workover of the well from a floating ship or barge.

When completing wells in marine locations, it would be desirable toperform the operation in such a way that no expensive permanent platformwas required. This problem has been partially solved by marine floorcompletions with flow lines along or under the marine floor from thewell head. The principal problem with wells of this type arises when itis necessary to workover the wells as by squeeze cementing, cleaning outthe wells, perforating at a new interval, or the like. Another problemis to make marine floor completions without the use of expensive andhighly specialized equipment and possibly divers.

An object of this invention is to provide a well head system permittingmarine floor completions which will still allow easy manipulation of thewell. Another object is to provide a marine floor well head arrangementwhich minimizes the use of specialized equipment and techniques forcompleting the well in the first place.

In general, I accomplish the objects of my invention by providing a slipjoint at the top of the casing string. This joint is long enough topermit raising the well head above the surface of the water where is canbe supported by a workover barge or ship and the workover operations canbe carried out much as if the well was on land. The technique alsopermits the original well head to be made up and connections to the wellhead to be made on the barge or ship so that ordinary well headcompletion equipment and techniques can be used. The entire assembly canthen be lowered to the marine floor by collapsing the casing slip joint.The well head need not be lowered completely to the marine floor as longas it is placed below the level affected by ships, Wave action and thelike.

In the drawing FIGURE 1 is a view, partly in cross section, of the topportion of a marine well completed in accordance with my invention.FIGURE 2 is another view, partly in cross section, of a preferredembodiment of my invention in which a seal is established between thetubing and casing below the casing slip joint and a positive seal isestablished between the two parts of the slip joint. FIGURES 3 and 4 areviews, in cross section, of portions of embodiments in which the slipjoint may be below the marine floor.

Considering the drawing in more detail, in FIGURE 1 a flat plate or padrests on the marine floor. A well casing 11 passes through a hole inplate 10. The casing is supported by a flange 12 which rests on plate10. On the top end of casing 11 is a tapered enlargement 13. Thisenlargement is one-half of a matching pair, the other half 14 of whichis on the bottom of outer section or barrel 15 of the slip joint.Clamping ring 16 completes the joint between casing 11 and barrel 15. Asealing gasket 17 is included between the faces of the flanges. Aconnection of this type is shown and described in more detail in theComposite Catalog for 1960-61, pages 1146 and 1147, published by WorldOil.

Outer pipe or barrel 15 of the slip joint surrounds inner portion ormandrel 18 of the joint. The bottom of the inner mandrel is threaded toreceive packing com- 3,217,805 Patented Nov. 16, 1965 pressing ring 19.Above ring 19, and filling a portion of the space between barrel 15 andmandrel 18, is packing 21. against flange 22 near the bottom of innermandrel 18. Mandrel 18 passes through the top of barrel 15 and isattached to a well head connection 22. This is a standard well headconnection except that some of the bolts which clamp cone 23 into bowl24 are eye bolts so that cables 25 can be attached. The cables areattached to a marking buoy (not shown) floating on the surface of thewater or held at some depth below the surface but retrievable withsuitable search and find devices. Cone 23 of the well head supports welltubing 20.

Also attached to the marking buoy is flexible tube 26 or a retrievableline for the flexible tube which extends down to a connection 27 passingthrough the wall of barrel 15 near the bottom of this pipe. Connection27 includes a flapper valve 28 which permits flow of liquid down theflexible tubing 26 and into the space above packing 21 between barrel 15and mandrel 18. The flapper or check valve prevents flow out of thespace between the barrel and mandrel. Any other check valve such as aball check may also be used, of course. The top of the barrel ispreferably turned in to form an inwardly directed flange 29. A smallclearance is provided between flange 29 and mandrel 18.

In FIGURE 2 the bottom of the figure is like FIGURE 1 except that asecond string of casing 31 is shown within outer surface casing 11.Cement 32 fills the space between the casing strings, port 33 beingprovided through casing 11 to permit filling to the top the annularspace between the casing strings.

In the apparatus of FIGURE 2, inner portion or mandrel 34 of the slipjoint is fixed to casing 11 by clamping ring 16 while the barrel portion35 moves up and down permitting raising and lowering of the well headattached to the top of barrel 35. The apparatus of FIGURE 2 is designedfor use in high pressure wells. In this case, the weight of the tubingand well head may not be quite enough to pull down the outer portion ofthe telescoping joint. Therefore, seals 36 and 37 are provided at thetop of mandrel 34 and the bottom of barrel 35 respectively. A tube 38passes through the wall of mandrel 34 just above seal 37. Flexible hose39 is attached to tube 38. Hose 39 passes to the buoy at the surface ofthe water so hydraulic pressure can be applied through the hose to helpforce barrel 35 down.

At the bottom of barrel 35 a clamping mechanism is provided to holdbarrel 35 down once it is forced to its bottom position. In thisclamping mechanism, bevelled flanges 41 and 42 are provided on mandrel34 and barrel 35 respectively. These flanges are held together byclamping elements 43. The outer surface of each element 43 is curved, soas solid ring 44 is raised by hydraulic cylinders 45, beveled flanges 41and 42 are released. When ring 44 is lowered, flanges 41 and 42 arelocked together. Hydraulic cylinders 45 are operated by hydraulicpressure applied through flexible hoses 46. At the bottom of mandrel 34,a portion 51 of smaller internal diameter is provided. An enlargedportion 52 on tubing string 53 is provided at a level which will beopposite portion 51 of mandrel 34 when the tubing is seated in the wellhead. A sealing element such as O-ring 54 is placed in enlarged portion52. This seal holds at least most of the pressure off of sliding seals36 and 37.

When the seal formed by sealing element 54 is broken by lifting thetubing, the entire pressure may be applied across seals 36 and 37. Itmay be desirable in some cases, therefore, to provide an additionalpositive seal across sliding seals 36 and 37. This is accomplished byinternal sleeve 55 with enlarged ends 56 and 57. The

The packing can be compressed by ring 19,

face to make a sliding seal with the cylinder.

ru 63 enlarged ends 56 and 57 carry sealing elements 58 and 59respectively. These elements protect sliding seals 36 and 37 from thefull well pressure when the tubing is lifted so sealing element 54 israised above cylinder 51. It will be apparent that sleeve 55 can be usedwithout seal 54 and seal 54 can be used without sleeve 55 if desired.

A production packer, for example of the type shown in the CompositeCatalog for 196061, pages 544 and 545, may also be used at the bottom ofthe well. This packer is set in the casing and provides a cylinder inwhich an enlarged portion or piston on the tubing slides. The piston hassealing elements around the outer sur- If the cylinder is long enough,the well head can be lifted from its lowest to its highest positionwithout removing the tubing piston from the cylinder of the productionpacker at the bottom of the well. In this way pressure can be kept offof the casing above the packer until after the well head has been raisedto the surface of the water. Then, if desired, the well can be killedwith mud or other heavy liquid before the tubing is pulled.

It is also possible to use a storm choke at the bottom of the well sothat when the tubing is pulled a valve closes to confine the pressure tothe bottom of the well.

For the sake of simplicity, a simple clamp ring 16 has been shown inboth FIGURES 1 and 2 to attach the slip joint assembly to the top ofcasing 11. It will be apparent, however, that locking elements such as43 operated by hydraulic cylinders such as 45 fixed to plate may be usedto facilitate making or releasing this connection by application ofhydraulic pressure from the surface of the water.

However the slip joint assembly is attached to the top of casing 11,once this connection is made, the well head in FIGURE 1 can be loweredto the position shown. In this position, the well head is far enoughbelow the surface of the water to permit ships to pass over the wellhead without touching it. Cables and hose 26 or retrieving line for hose26 are attached to a buoy, not shown, so that if it is desired toworkover the well, it is only necessary for a drilling ship or barge tocome to the buoy and lift on the cables and hose to raise the well headto the deck of the ship or barge. The well can then be cleaned out orotherwise manipulated in much the same way as if the well was on dryland.

The tubing sections extending upwardly and outwardly from the well headshould usually include flexible portions to facilitate handling of thewell head. When the well head is again lowered into the position shownin FIGURE 1, an oil or grease, preferably heavier than the water outsidethe assembly, is introduced through hose 26 and connection 27 into theannular space between barrel 15 and mandrel 18 to avoid corrosion. If aseal is provided between the top of barrel 15 and the outer surface ofmandrel 18, then the oil can, of course, be lighter than the water. Ifsuch a seal is used, however, the liquid between the barrel and mandrelmust be displaced through hose 26 as the well head is raised and must beadded to the space as the well head is lowered. To permit such movement,flapper valve 28 must be removed; The liquid between pipes 15 and 18 canalso, of course, be an aqueous solution or gel containing a corrosioninhibitor if desired.

Many variations and modifications are possible. For example, while myinvention is principally applicable to open sea locations where largeship traflic and serious wave actions are problems, it will be apparentthat the invention is also applicable to inland waters such as riversand lakes. When the term marine is used, I intend the term to includeany water-covered area where a well may be drilled.

In FIGURE 1 a particular type of well head is shown. One of theadvantages of my invention is that since the well head is always made upabove the water, almost any type of well head can be used. The onlyrequirement is that some means such as eye bolts be used to which alifting cable can be attached.

In some wells the tubes extending from the sides of the well head may beclosed by valves, or the well head openings may be closed by plugs. Anexample of such an arrangement is found in the Composite Catalog of OilField Equipment and Services for 1960-1961, page 880. The main tubingextending from the top of the well may be curved to lie on the marinefloor along which it may extend to separators, flow tanks, and the like.An arrangement of this type is shown in US. Patent 3,052,299. Theseparators and tanks may be on marine platforms as shown in the Oil andGas Journal for July 10, 1961, page 59, or on shore, for example. Thetubing may also be attached to a flexible high pressure line (not shown)which extends to the water surface to the buoy which supports cables 25.The flexible highpressure line can be closed by a valve so that a tankeror barge can drop anchor and take production through the tubing withoutraising the well head. Examples of such equipment are illustrated in US.Patent 3,004,612 and Oil and Gas Journal, September 24, 1962, page 107.

The apparatus in FIGURE 1 is shown extending above the marine floor. Itwill be apparent, however, that the top portion of casing 11 can serveas barrel 15 as shown in FIGURE 3. In this case, everything but the wellhead will be below the marine floor. A top plate 62 is simply clamped ontop of enlarged portion 13 of casing 11. This prevents pulling mandrel18 from the well without releasing clamp 16, but still allows mandrel 18to be raised or lowered in barrel 11 (FIGURE 3) to the limits imposed bypacking gland stop 22 (FIGURE 2). If the top section of casing 11, or ofcasing 31 in FIG- URE 2, is to serve as the barrel for the slip joint,it cannot be subjected to wear during the drilling operation. Therefore,during drilling operations, a wear sleeve (not shown) should be usedinside the portion of the casing which is to serve as the barrel of theslip joint. This is most simply done by hanging a short liner stringthrough the top casing joint as shown, for example, in US. Patent2,683,086. The wear sleeve is then removed before the mandrel of theslip joint is inserted. The top section of the casing (barrel of theslip joint) may be attached to the remainder of the well casing by anordinary collar or by any other suitable means. The collar may have alefthand thread, permitting the top portion of the casing to be standardcasing easily removed after the drilling operation and cementingoperation are completed. Such a lefthand thread detachable connection isshown, for example, in the Composite Catalog of Oil Field Equipment andServices for 1960-1961, page 5248. This top portion can then be replacedby a new length which can serve as the slip joint barrel.

Still another arrangement is shown in FIGURE 4. Here the top plate 62 islike in FIGURE 3 except that hanging from the bottom of the plate is aliner sleeve 63 which serves as the outer barrel of the slip joint.Still other arrangements are, of course, possible.

In case of deep water, more than one slip joint may be employed. Thesejoints may be arranged on top of each other or they may be nestedtogether with each mandrel acting as the barrel for the next internalmandrel as in a spy glass having several telescoping sections. It isalso possible to lengthen casing 11 between flanges 12 and 13 in orderto use shorter slip joints in deep water.

In FIGURE 2 hydraulic cylinders 45 are shown attached to barrel 35. Itwill be apparent that the entire system of locking elements 43 andhydraulic cylinders 45 can be inverted so the cylinders can be attachedto plate 10 or flange 12 on the marine floor.

Also in FIGURE 2, the bottom of mandrel 34 is shown with two sections 51and 61 of reduced internal diameter near the bottom. It is possible tomake the mandrel of uniform internal diameter and use packer and slipssystems such as those shown in the Composite Catalog for 1960-61, pages544 and 545, to provide the cylinders of reduced diameter in whichsealing elements 54 and 59 can be set. Such packers may be set in casing11 or 31 as well as in mandrel 34.

The pad or plate on the marine floor may be of metal, as shown, or ofother materials such as reinforced concrete. The plate may be turned upon the edges to form a pan which may be filled with heavy materials suchas barite to stabilize the equipment at the top of the well.

Many other variations will be apparent to those skilled in the art. I donot wish, therefore, to be limited to the specific embodiments shown anddescribed, but only by the limitations of the following claims.

I claim:

1. Apparatus for completing a well at a marine location comprising aslip joint made up of an inner cylindrical hollow mandrel and an outerbarrel, means for forming a sliding seal between said mandrel and saidbarrel, means for connecting the bottom of said slip joint to the wellcasing, a well head attached to the top of said slip joint, said Wellhead including means for supporting a tubing string therein, and meansfor raising and lowering said well head, the length of said slip jointbeing sufficient to permit said well head to be lifted above the surfaceof the water, and lowered to a level sufficiently low to avoid ships,serious wave action and the like.

2. The apparatus of claim 1 in which the external diameter of the hollowmandrel is sufficiently smaller than the internal diameter of the outerbarrel to provide an annular space between the mandrel and barrel, a passage into the annular space between the barrel and mandrel, and means tofill this space with a protective material such as a non-corrosiveliquid.

3. The apparatus of claim 1 in which said means for raising and loweringsaid well head includes cables attached to a buoy floating on thesurface of the water.

4. Apparatus for completing a well at a marine location comprising aslip joint made up of an inner cylindrical hollow mandrel and an outerbarrel, means for forming a sliding seal between said mandrel and saidbarrel, means for connecting the bottom of said slip joint to the wellcasing, a well head attached to the top of said slip joint, said wellhead including means for supporting a tubing stn'ng therein, a sleeveinside said slip joint, said sleeve having at one end a seal against theinternal surface of said mandrel and at the other end a seal against theinternal surface of said barrel, thus forming a seal across the slipjoint, and means for raising and lowering said well head, the length ofsaid slip joint being sufiicient to permit said well head to be liftedabove the surface of the water, and lowered to a level sufiiciently lowto avoid ships, serious wave action and the like.

5. The apparatus of claim 4 including a string of tubing passing throughsaid slip joint and into said casing, and means for forming a sealbetween said tubing and the well wall at a level which isolates fromwell pressure the seal in said slip joint.

6. The apparatus of claim 5 including a sleeve inside said slip joint,said sleeve having at one end a seal against the internal surface ofsaid mandrel and at the other end a seal against the internal surface ofsaid barrel, thus forming a seal across the slip joint.

7. Apparatus for completing a well at a marine location comprising aslip joint made up of an inner cylindrical hollow mandrel and an outerbarrel the external diameter of the hollow mandrel being suflicientlysmaller than the internal diameter of the outer barrel to provide anannular space between the mandrel and barrel, a sliding seal at each endof the annular space between said mandrel and said barrel, a passageinto said annular space, means to apply pressure to said annular spaceto collapse said slip joint to its closed position, means for connectingthe bottom of said slip joint to the well casing, a Well head attachedto the top of said joint, said well head including means for supportinga tubing string therein, and means for lowering and raising said wellhead, the length of said slip joint being suflicient to permit said Wellhead to be lifted above the surface of the water and lowered to a levelsufiiciently low to avoid ships, serious wave action and the like.

8. The apparatus of claim 7 in which said means for raising and loweringsaid well head includes cables at tached to a buoy floating on thesurface of the water.

9. Apparatus for completing a well at a marine location comprising aslip joint made up of an inner cylindrical hollow mandrel and an outerbarrel, the external diameter of the hollow mandrel being suflicientlysmaller than the internal diameter of the outer barrel to provide anannular space between the mandrel and barrel, a sliding seal at each endof the annular space between said mandrel and said barrel, a passageinto said annular space, means to apply pressure to said annular spaceto collapse said slip joint to its closed position, means for connectingthe bottom of said slip joint to the well casing, a well head attachedto the top of said joint, said well head including means for supportinga tubing string therein, a sleeve inside said slip joint, said sleevehaving at one end a seal against the internal surface of said mandreland at the other end a seal against the internal surface of said barrel,thus forming a seal across the slip joint, and means for raising andlowering said well head, the length of said slip joint being sufiicientto permit said well head to be lifted above the surface of the water,and lowered to a level sufficiently low to avoid ships, serious waveaction and the like.

10. The apparatus of claim 9 including a string of tubing passingthrough said slip joint and into said casing, and means for forming aseal between said tubing and the well wall at a level which isolatesfrom well pressure the seal in said slip joint.

11. The apparatus of claim 10 including a sleeve inside said slip joint,said sleeve having at one end a seal against the internal surface ofsaid mandrel and at the other end a seal against the internal surface ofsaid barrel, thus forming a seal across the slip joint.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS11/ 1960 Great Britain.

BENJAMIN HERSH, Primary Examiner.

1. APPARATUS FOR COMPLETING A WELL AT A MARINE LOCATION COMPRISING ASLIP JOINT MADE UP OF AN INNER CYLINDRICAL HOLLOW MANDREL AND AN OUTERBARREL, MEANS FOR FORMING A SLIDING SEAL BETWEEN SAID MANDREL AND SAIDBARREL, MEANS FOR CONNECTING THE BOTTOM OF SAID SLIP JOINT TO THE WELLCASING, A WELL HEAD ATTACHED TO THE TOP OF SAID SLIP JOINT, SAID WELLHEAD INCLUDING MEANS FOR SUPPORTING A TUBING STRING THEREIN, AND MEANSFOR RAISING AND LOWERING SAID WELL HEAD, THE LENGTH OF SAID SLIP JOINTBEING SUFFICIENT TO PERMIT SAID WELL HEAD TO BE LIFTED ABOVE THE SURFACEOF THE WATER, AND LOWERED TO A LEVEL SUFFICIENTLY LOW TO AVOID SHIPS,SERIOUS WAVE ACTION AND THE LIKE.